it seems like there are a lot of those oddities but I wonder if it really happens as often as it seems or if those examples are just brought up a lot. I'm going to look at that at some point - offensive value for any given player can fluctuate year-to-year, so why not defense? Maybe defensive value doesn't fluctuate more than offensive value. It does seem like it does, though.

I agree. If Miguel Cabrera had a slugging percentage of .350 for a couple hundred at bats, no one would consider SLG broken or unreliable.

I'd argue Cabrera was slumping terribly. Which I guess brings the next point - can you "slump" in the field for an entire season? Again, Trout was considered GG quality last year, and this year, he's considered to be easily replaceable in the field.

Has anyone looked at Trout play the field this year and said "Damn, what's wrong with him?" Maybe they have and I haven't heard it.

Why can't you slump in the field?

Everything I've read about fielding stats say that they don't normalize until you have a big enough sample. Like hitting stats.

You need 60 plate appearances for a hitter's K rate to be reliable. 120 for walk rate. 320 for SLG and 460 OBP. 910 (a year and a half for a starter!) for BA.

You really need three years for UZR.

Here's what Fangraphs says:

Since defensive statistics are still relatively new, they should not be taken as 100% dead accurate. Before drawing any conclusions about a player’s defense, look at a full three years of defensive data, drop the decimal points and take an average, and compare UZR scores with other defensive metrics (DRS, TZL, etc.). By taking a broader picture, you will help ensure that you’re not being over-confident or overstating a player’s defensive abilities.

In general, UZR scores can be broken down into the following tiers. This is a good shorthand way of evaluating a player’s defensive ability level:

Defensive Ability

UZR

Gold Glove Caliber

+15

Great

+10

Above Average

+5

Average

0

Below Average

-5

Poor

-10

Awful

-15

Things to Remember:

? Beware of sample sizes! If a player only spent 50 innings at a position last season, it’d be a good idea not to draw too many conclusions from their UZR score over that time. Like with any defensive statistic, you should always use three years of UZR data before trying to draw any conclusions on the true talent level of a fielder.

? UZR uses Baseball Info Solutions (BIS) data in calculating its results. It’s important to note that this data is compiled by human scorers, which means that it likely includes some human error. Until FIELDF/x data gets released to the public, we are never going to have wholly accurate defensive data; human error is impossible to avoid when recording fielding locations by hand, no matter how meticulous the scorers. That said, BIS data is still the best, most accurate defensive data available at this time, so just be careful not to overstate claims of a player’s defensive prowess based solely on defensive stats.

? Since UZR is a counting statistic like RBIs or HRs, the more playing time a player accrues, the higher (or lower) their UZR will be. In order to compare players with different amounts of playing time, UZR can be scaled on a 150 game basis (UZR/150). If you want to compare a player with 90 games played to someone with 140, UZR/150 would be the way to do so.

? UZR is park-adjusted, meaning it adjusts for the fact that fielders have to deal with odd quirks in certain ballparks.

Posted by mfahie on 8/14/2013 7:40:00 AM (view original):Even if the defensive metrics are accurate, which is debatable, I have an even bigger problem with the way they are weighted in the calculation.

I have a really hard time imagining that, for instance, two right fielders in the major leagues could be so far apart defensively that it erases an almost 250 point difference in OPS. Especially when their raw defensive numbers (which I admit are imperfect, but are at least easy to see) are more or less the same.

Ever since they've started to publish the various all-in-one defensive stats, I've felt strongly that they are overrated with respect to hitting.

Just watching Cuddyer you can see that he has no range at all. Is it really unreasonable to think that a guy who runs in cement in right field could cost his team a significant amount of runs?

And, for what it's worth, Fangraphs has Cuddyer at 1.8 WAR and Aoki at 0.7. So Aoki's defense doesn't erase the huge offensive difference between the two.

Posted by mfahie on 8/14/2013 7:40:00 AM (view original):Even if the defensive metrics are accurate, which is debatable, I have an even bigger problem with the way they are weighted in the calculation.

I have a really hard time imagining that, for instance, two right fielders in the major leagues could be so far apart defensively that it erases an almost 250 point difference in OPS. Especially when their raw defensive numbers (which I admit are imperfect, but are at least easy to see) are more or less the same.

Ever since they've started to publish the various all-in-one defensive stats, I've felt strongly that they are overrated with respect to hitting.

Is that because fielding just seems like it's got to be easier than hitting? I feel the same way you do, I just wonder if there's something I'm not getting. Across baseball, I am sure more WAR is accumulated on offense than fielding alone.

Other than at a few positions, I think most major league non-pitchers get to the bigs based on their hitting, so maybe we should expect more variation in fielding. I think the average RF touches the ball about 4 times/game, probably close to the number of times they get to bat per game. On average, half of those touches result in an out on the play but range factor is going to be impacted by park, just like offense is. Cuddyer should theoretically get more opportunities because there are more balls in play in Coors than other parks so a similar range factor to other fielders probably understates his lack of range. One thing that is difficult is that it's not that easy to watch a batter line a single past a player or hit a double in the gap just past a fielder and always know, "Oh, 'so-and-so' would have caught that, or cut that off, or not allowed the runner to advance another base." Hitters have different skill levels but have to stand in the same batters box and deal with the same strike zone. Fielders have different skill levels, wide areas to cover, and can also improve or worsen their chance of preventing hitter/runner advancement based on where they are positioned, which can vary batter to batter and might be impacted by coaches, rather than the fielder himself. More variables, I guess, to make it tougher to measure and tougher to accept the metrics. I know they are working on measuring fielder position, ball speed and hang time, and fielder time/distance to ball. Will be interesting to see how the defensive metrics stand up when that data is available.

Posted by MikeT23 on 8/14/2013 11:41:00 AM (view original):If you need three years of defensive stats to really know, you really can't argue that they be included for individual season awards. Right?

That's an interesting point but I think the three years is more about establishing talent level. The awards are based on production, which can be above or below an expected/perceived talent level. I guess that's a debate, too - is Chris Davis just performing above his true talent level (as established by his historical record) for a period of time, or has his talent level changed this year to the point that this is what we should expect in the future from him, or is talent level variable even in-season or during short time frames instead of more stable.

I think there's a lot more in play in the field. At the plate, you're basically trying to advance yourself, or a runner, to the next station.

In the field, you're positioning yourself(or being positioned by the coaching staff) to prevent a certain outcome. Playing deep, cheating lines, cheating middle, whatever, but the outcome may be giving up bag to prevent two from being taken. Maybe all that's calculated into the defensive metrics but I'm not even sure it matters. I know, when a coach moved me to where I wasn't comfortable, I'd cheat my way back during the wind-up. Or take my first step at contact back to where I wanted to be. So a player could be way out of position.

Posted by MikeT23 on 8/14/2013 11:41:00 AM (view original):If you need three years of defensive stats to really know, you really can't argue that they be included for individual season awards. Right?

That's an interesting point but I think the three years is more about establishing talent level. The awards are based on production, which can be above or below an expected/perceived talent level. I guess that's a debate, too - is Chris Davis just performing above his true talent level (as established by his historical record) for a period of time, or has his talent level changed this year to the point that this is what we should expect in the future from him, or is talent level variable even in-season or during short time frames instead of more stable.

I guess I phrased it improperly. In the case of Trout, it was argued that he was considerably more valuable in CF than Cabrera was at 3B. This was based of DWAR. Which, it seems, we're questioning as being legit for various reasons. So a big DWAR season is questionable. Whereas, with hitting, we have many different stats to consider. You don't have to accept WAR as a defining stat because you get there with the "old school" numbers.

"UZR uses Baseball Info Solutions (BIS) data in calculating its results. It’s important to note that this data is compiled by human scorers, which means that it likely includes some human error. Until FIELDF/x data gets released to the public, we are never going to have wholly accurate defensive data; human error is impossible to avoid when recording fielding locations by hand, no matter how meticulous the scorers."

So not only does it take 3 years to "normalize" there could potentially be a good deal of human error in determining the stat. Awesome.

"UZR tries to record a player’s likely true talent and estimate his future performance based on the nuances of the batted ball and the player’s response to those nuances. It is not trying to capture exactly what happens on the field according to some arbitrary categories, like most of the offensive metrics (which make no distinction between a lucky ground ball bleeder through the “5-hole” or a clean, line drive base hit to the outfield), even the advanced ones like wOBA or linear weights."

This is coming from an article describing the ins and out of UZR. It's basically saying it's more like FIP or a statistic that describes how well a batter hits a baseball, rather than how many hits he gets. And it could take 3 years or more to get a good accurate sense of what a player is defensively. At one point in the article it says you may not even know after 10 years.

So we're calculating this number into WAR, even though we shouldn't because 1 year of these calculations may not mean anything really, there's human error because scorers are basically guessing where the ball and landed and marking that into their computer, AND it's supposed to read more like FIP or whatever in determining future results or a ballplayer, more than a determination of what the player has actually done. Yea, putting little stock into this number.

I get errors, but how can someone slump in the field when it comes to range and whatnot? Hitting a baseball is a difficult thing to do. It's much more difficult than running to a spot and catching baseball. I get slumping when hitting, not so much for running after a ball and catching it.

For example, if you see a player with a one year UZR of +10, think +5! He might not have actually played well at all, or he might have played off the charts, but our best guess as to how he played was +5. If you see a +10 after 1 month and you have no other data or information on a player, think of that as a +1.5 (regress it 85% toward the mean). Literally forget the +10. It means nothing. It does NOT mean that he played like a +10 fielder and we are just regressing it because we are not sure that his true talent is +10. We are regressing it (heavily) because not only do we not think that he has +10 talent, but because we don’t think that he played like as +10 fielder either.

Ha - so if you see a number after a year, ignore it! Pretend it's something else!

Posted by burnsy483 on 8/14/2013 12:32:00 PM (view original):"Why can't you slump in the field?"

I get errors, but how can someone slump in the field when it comes to range and whatnot? Hitting a baseball is a difficult thing to do. It's much more difficult than running to a spot and catching baseball. I get slumping when hitting, not so much for running after a ball and catching it.

Getting to a hard hit grounder up the middle is also hard to do (just ask Jeter). I don't think it's unreasonable to see variances in fielding performance.

Posted by burnsy483 on 8/14/2013 12:34:00 PM (view original):More from the article:

For example, if you see a player with a one year UZR of +10, think +5! He might not have actually played well at all, or he might have played off the charts, but our best guess as to how he played was +5. If you see a +10 after 1 month and you have no other data or information on a player, think of that as a +1.5 (regress it 85% toward the mean). Literally forget the +10. It means nothing. It does NOT mean that he played like a +10 fielder and we are just regressing it because we are not sure that his true talent is +10. We are regressing it (heavily) because not only do we not think that he has +10 talent, but because we don’t think that he played like as +10 fielder either.

Ha - so if you see a number after a year, ignore it! Pretend it's something else!

No thanks.

If after a month, a player was hitting .400, would you think of that player as a .400 hitter or would you expect that to regress?